This invention relates to glow discharge apparatus for deposition of films more particularly to apparatus design for film deposition on cylindrically shaped substrates, e.g., drum photoreceptor members.
Many different kinds of glow discharge apparatus have been designed for the deposition of thin films on surfaces of different shaped workpieces or substrates. Of particular interest is the deposition of amorphous silicon (a-Si) and, more particularly, a-Si:H produced during the r.f. glow discharge process. [W. E. Spear and P. G. Le Comber, Solid State Communications, Vol. 17, p. 1193 et seq. (1975), W. E. Spear, Advance Physics, Vol. 26, p. 28 et seq. (1977)]. A typical example of the glow discharge systems now employed is shown in the article of J. C. Knights entitled "Substitutional Doping in Amorphous Silicon", AIP Conference Proceedings, No. 31, American Institute of Physics, 1976.
An important application of a-Si:H thin films is a photoreceptor member in electrographic systems. Many such systems today require cylindrically shaped photoreceptor members. While the glow discharge system disclosed in the above-mentioned J. C. Knights article is suitable for flat plate workpieces or substrates, it is not best suited for cylindrically shaped workpieces.